What is best practice to query datas use java?

[Joey777210]

Looking for best practice, I'm using raw HTTP APIs now, but is't not convenience for write codes and debug.
Thans for anyones answer!

[fstab]

I'm not quite sure what you mean. Usually you store metric data in a time series database like Prometheus and query that data using the PromQL query language. What do you want to achieve?

[Joey777210]

If I want to query data in a Java project, is the best way writing PromQL in a String and pass to Prometheus throw HTTP? Is there a query Lib?
In this way, do I make the question clear?

[fstab]

Prometheus is a time series database. That means it does not only have the current value of metrics, but also the history of previous values.

A good example why this is needed is a request count for an HTTP service, something like http_requests_total. If you just know the current value, it tells you nothing. However, if you know how much the count has increased over the past 5 minutes, this is valuable information, because it gives you the the request rate based on a 5 minute time window.

For many cases, you need the time series data for meaningful information. You can only get that when querying Prometheus, not from a client library.